An Iridium/Aluminum Cooperative Strategy for the β‐C(sp3)‐H Borylation of Saturated Cyclic Amines.

Despite the widespread success in the functionalization of C(sp2)−H bonds, the deliberate functionalization of C(sp3)−H bonds in a highly site‐ and stereoselective manner remains a longstanding challenge. Herein, we report an iridium/aluminum cooperative catalytic system that enables the β‐selective C−H borylation of saturated cyclic amines and lactams. Furthermore, we have accomplished an enantioselective variant using binaphthol‐derived chiral aluminum catalysts to forge C−B bonds with high levels of stereocontrol. Computational studies suggest that the formation of a Lewis pair with the substrates is crucial to lower the energy of the transition state for the rate‐determining reductive elimination step. [ABSTRACT FROM AUTHOR]